When I switched on the Thinkpad first time I got error codes 161, 192 and 163. According to manual I should check the CMOS backup battery and I found out that CMOS backup battery was bad, when I measured the voltage it showed 0 V. So

I changed the CMOS backup battery, now the battery shows 3 V.

Now when I switch on the Thinkpad with the new CMOS battery, I get error codes 163 and 173. The window with error codes 163 and 173 pops up, I press OK, window with time and date settings pops up. I set the time and date, I have to change the time and date from default values (2000-01-01; 00:00:00) to actual values and I confirm it by pressing OK button.

I hear double beep and restart is performed. After restart no error code appears and MS-DOS from HDD 1 is loaded.

I switch off the Thinkpad.

Now when I switch on the Thinkpad second time, again the error codes 163 and 173 appears even though I set the time and date before, window with error codes 163 and 173 pops up, I press OK, window with time and date settings pops up. I just confirm the time and date because the actual time and date remain and I confirm it by pressing OK button.

I hear double beep and restart is performed. After restart no error code appears and MS-DOS from HDD 1 is loaded.

I switch off the Thinkpad.

When I go to Easy setup and then Test window and I perform test with all components (System board, Memory, Display, HDD1, FDD1, Parallel, Serial, DSP, Infrared, etc) I get test result OK for each component. When I press CTRL + A the window with connected FRU parts appears showing that all parts are connected instead Docking Unit.

Does anybody know how to solve this problem with error codes 163 and 173 which are displayed every time when I switch on my Thinkpad?

About the backup battery, I do not have available original backup battery FRU 02K6502 at the moment.

I had at home normal (blank) coin battery type 2025. So I used standard 3V lithium battery type 2025 from Duracell.

Red wire is soldered to " + " side of coin batteryBlack wire is soldered to " - " side of coin batteryPolarity seems to be OK.

The battery is wrapped by insulated tape.

I measured the backup battery voltage before as well as after I soldered on the wires.I measured the voltage directly from the tiny contacts of the white 2-pins connector.I measured the voltage directly between the motherboard and white 2-pins connector, there is a original soldered joint from factory.In all cases it shows me 3 V.

I could learn to live with these error codes 163 and 173 during the booting procedure and confirm the time and date setting each time when I switch on the Thinkpad but worst problem is that I can not connect the CD ROM drive in Ultraslim bay because in this case it does not work at all.